Control valve for an engine cooling circuit

ABSTRACT

A control valve ( 10 ) for a fluid circulation circuit comprises a body ( 12 ) which is equipped with a fluid inlet ( 18 ) and at least two fluid outlets ( 20, 22  and  24 ) and which delimits a cylindrical housing for an adjusting member ( 26 ) able to rotate about an axis of rotation (XX) and to adopt various angular positions in order to control the distribution of fluid through the outlets. The body ( 12 ) comprises an end wall ( 14 ) into which the fluid inlet ( 18 ) opens and a cylindrical side wall ( 16 ) into which the fluid outlets open at axial heights and at angular positions that are chosen with respect to the axis of rotation (XX). The rotary member ( 26 ) comprises a truncated end ( 38 ) facing toward the end wall ( 14 ), this making it possible to have control over the fluid outlets using a law defined as a function of the angular position of the rotary member in the valve body.

[0001] The invention relates to a control valve for a fluid circulationcircuit, and to a circuit equipped with such a valve.

[0002] It is aimed more specifically at providing a control valveintended for a motor vehicle engine cooling circuit.

[0003] Such a cooling circuit has, running through it, a coolant,usually water, to which an antifreeze is added, which flows in a closedcircuit under the action of a circulation pump.

[0004] In general, such a cooling circuit comprises several branches,including a branch that contains a cooling radiator, a branch whichconstitutes a bypass of the cooling radiator and a branch which containsa radiator, also known as a “unit heater”, that serves to heat thecabin.

[0005] It is known practice to employ a thermostatic valve whichcomprises a fluid inlet connected to the outlet of the engine and twofluid outlets which correspond respectively to the branch containing thecooling radiator and to the branch forming the bypass.

[0006] When the engine is started from cold, and as long as thetemperature of the coolant has not reached a certain threshold level,the valve causes the coolant to circulate through the bypass branch,short circuiting the cooling radiator. As soon as the temperature of thecoolant reaches and exceeds the aforementioned threshold level, thecoolant passes through the cooling radiator and avoids the bypassbranch.

[0007] In general, the coolant circulates constantly through the branchcontaining the heating radiator, the heating of the cabin then beingobtained by mixing a stream of cold air and a stream of hot air whichhas swept across the heating radiator. It is also known practice toprovide a separate valve on the heating radiator in order to adjust theflow rate of coolant passing through it.

[0008] In existing embodiments, use is made of control valves whichallow independent control over the flow rate of coolant through thevarious branches of the cooling circuit of an engine, so as to optimizethe engine temperature and the heating of the cabin. However, thecontrol valves do not provide the valve-control system or the enginecomputer with information about the state of the cooling circuit and areunable to diagnose faults or breakdowns in the cooling circuit.

[0009] It is also known practice to apply sensors external to the valvein order to monitor the operation of the heat transfer fluid. However,installing such sensors is expensive, not very reliable, and alsorequires recourse to be made to several connectors in order to transmitthe measured values to the computer of the vehicle and to the valvecontrol system.

[0010] The valves in current cooling circuits are therefore not equippedto detect any malfunctioning and, if appropriate, to provide a diagnosisthereof, so that operation of the valves can be altered.

[0011] The invention aims to improve the situation.

[0012] To this end, it proposes a control valve comprising built-insensors and intended for a fluid circulation circuit which, in apreferred embodiment of the invention, constitutes a motor vehicleengine cooling circuit and is equipped with built-in sensors to slavethe position of the control valve according to at least one parametercharacteristic of the state of the cooling circuit and measured by thesensors, and to diagnose any malfunctioning of the cooling circuit.

[0013] In this particular application, the invention is aimed ataffording a valve which allows independent control of the flow rate ofcooling fluid through the various branches of the engine coolingcircuit, so as to optimize the engine temperature and the heating of thecabin.

[0014] The invention is thus more particularly aimed at a control valvefor a fluid circulation circuit, comprising a body which is equippedwith at least one fluid inlet and at least two fluid outlets, and whichdelimits a housing for an adjusting member able to rotate about an axisof rotation and to adopt various angular positions in order to controlthe distribution of fluid through the outlets.

[0015] According to one general definition of the invention, the bodycomprises an end wall into which the fluid inlet opens and a side wallinto which the fluid outlets open, at axial heights and at angularpositions that are chosen with respect to the axis of rotation, and theadjusting member comprises a shaped part for controlling the outlets offluids with a law defined as a function of the angular position of therotary member in the valve body.

[0016] In an advantageous embodiment, the body delimits a cylindricalhousing for the adjusting member, the side wall is a cylindrical wall,and the shaped part is a truncated end facing toward the end wall.

[0017] It is thus possible to control the flow rate of fluid through thevarious outlets of the valve, and to do so as a function of the angularposition given to the adjusting member of the valve.

[0018] In this way, it is possible to control the distribution of fluidin accordance with a predefined law.

[0019] Such a valve may thus equip a fluid circulation circuit,particularly a motor vehicle engine cooling circuit, to provideindependent control over the flow rates of cooling fluid through thevarious branches of the circuit.

[0020] Advantageously, the truncated end comprises a generally flat facewhich, with the axis of rotation, forms a chosen angle of close to 45°.

[0021] In the valve of the invention, at least one of the fluid outletsmay be a radial nozzle or alternatively a tangential nozzle.

[0022] In one particular application, the valve has three fluid outlets.

[0023] In one embodiment of the invention, the adjusting member iscovered with a split ring made to rotate as one with it by a projectinglug that the adjusting member has.

[0024] In this case, the split ring is advantageously made of a materialwith a low coefficient of friction. Such a split ring advantageously hasan outside diameter slightly greater than the inside diameter of thevalve body prior to mounting and an inside diameter slightly greaterthan the diameter of the adjusting member after mounting.

[0025] It is advantageous for the split ring to cover a region of theadjusting member which is equipped with circular grooves. These groovesactually guarantee that the split ring is pressed firmly against theinterior wall of the body, thus ensuring a good seal during operation.

[0026] As an alternative or as a supplement, the truncated end of theadjusting member may comprise a duct, having a chosen shape,advantageously the shape of an arc of a circle, making it possible tooptimize the progressiveness of opening.

[0027] As an alternative or as a supplement, the adjusting member may beequipped with a sealing shoe, preferably mounted on a spring, making itpossible to obtain sealing, particularly on the most critical branch ofthe circuit.

[0028] In another embodiment, the adjusting member comprises, at theopposite end to the truncated end, two roughly diametrically opposedcylindrical wall portions for controlling one of the fluid outlets. Thisis particularly suitable when this fluid outlet has a large crosssection and avoids increasing the diameter of the valve body. This isbeneficial when there is a desire to isolate a chosen branch of thecircuit.

[0029] The control valve advantageously comprises drive means able todrive the adjusting member by means of a drive wheel forming part of areduction gearbox for bringing it into chosen angular positions withrespect to the valve body.

[0030] As a supplement, the valve comprises a microprocessor foroperating the drive means.

[0031] According to another aspect of the invention, the adjustingmember comprises at least one internal sensor for measuring valuesrelating to the operation of the fluid circulation circuit.

[0032] In a first embodiment, the internal sensors are sensors thatsense the presence of air in the circuit.

[0033] In a particular application, the adjusting member comprises amachined duct extending over the entire length of the adjusting member,to house the sensors.

[0034] Advantageously, a first end of the sensors passes through thelower end of the adjusting member facing toward the end wall, at achosen point, so as to be in contact with the fluid.

[0035] In a second embodiment, the sensors are temperature sensors andthe machined duct comprises a lower end made of brass, in contact withthe fluid, in which to house the first end of the temperature sensors.

[0036] It is advantageous for the second end of the sensors to passthrough the upper end of the valve toward the outside to transmit thevalues measured by the sensors.

[0037] As a supplement, the second end of the sensors is connected toinformation transmitting means for transmitting the values measured bythe sensors to the microprocessor and/or to a computer.

[0038] In one embodiment, the information transmitting means comprisecircular electrical-contact tracks.

[0039] In this embodiment, the information transmitting means may alsocomprise plugs connected to the circular tracks for transmitting thevalues originating from the sensors.

[0040] The circular tracks may be situated on a moving part of the valvewhereas the plugs are situated on a fixed part of the valve.

[0041] As an alternative, the circular tracks may be situated on a fixedpart of the valve whereas the plugs are situated on a moving part of thevalve.

[0042] In particular, the moving part of the valve is the drive wheel ofthe drive means.

[0043] The control valve advantageously comprises a connector, connectedto the information transmitting means of the valve to transmit themeasured values to the microprocessor and/or to the computer.

[0044] According to another aspect, the invention relates to a fluidcirculation circuit which comprises a control valve as definedhereinabove, the fluid inlet of which is connected to a fluid source andthe fluid outlets of which are connected respectively to branches of thecircuit.

[0045] In one preferred application, the circuit is produced in the formof a cooling circuit for cooling the engine of a motor vehicle, throughwhich a coolant flows under the action of a circulation pump. In thisapplication, the control valve is a three-way valve, the fluid inlet ofwhich is connected to a coolant inlet originating from the engine, andthe three fluid outlets of which are connected respectively to a firstbranch of the circuit which contains a cooling radiator, to a secondbranch of the circuit which constitutes a bypass of the coolingradiator, and to a third branch of the circuit which contains a unitheater for heating the cabin.

[0046] In the description which follows, given solely by way of example,reference is made to the attached drawings in which:

[0047]FIG. 1 is a perspective view of a control valve, of the three-waytype, according to a first embodiment of the invention;

[0048]FIG. 2 is a view from above of the valve of FIG. 1;

[0049]FIGS. 3 and 4 are side views of the valve of FIGS. 1 and 2;

[0050]FIG. 5 is a view in section on V-V of FIG. 3;

[0051] FIGS. 6 to 8 are views in section on VI-VI, VII-VII and VIII-VIIIof FIG. 4 respectively;

[0052]FIG. 9 is a perspective view of an adjusting member of a controlvalve, according to another embodiment of the invention, which isequipped with a duct;

[0053]FIGS. 10 and 11 are two side views of the rotary member of FIG. 9;

[0054] FIGS. 12 to 15 are views in section corresponding to FIGS. 5 to 8respectively for a control valve equipped with a rotary member accordingto FIGS. 9 to 11;

[0055]FIG. 16 is a perspective view of an adjusting member equipped witha sealing shoe;

[0056]FIG. 17 is a side view of the adjusting member of FIG. 16;

[0057]FIG. 18 is a view in section on XVIII-XVIII of FIG. 17;

[0058] FIGS. 19 to 22 are various views in section, correspondingrespectively to FIGS. 5 to 8, of a control valve equipped with anadjusting member according to FIGS. 16 to 18;

[0059] FIGS. 23 to 30 are various views, similar to FIGS. 1 to 9respectively, of a control valve according to another embodiment;

[0060]FIG. 31 is a perspective view of an adjusting member equipped witha split ring;

[0061]FIG. 32 is a side view corresponding to FIG. 31;

[0062]FIG. 33 is a view in section on XXXIII-XXXIII of FIG. 32;

[0063]FIG. 34 shows, in each instance, three different sectional viewsof the valve for angular positions of the adjusting member, these beingnumbered from 1 to 21, which follow on from one another in 15-degreeincrements in the clockwise direction;

[0064]FIG. 35 depicts a motor vehicle engine cooling circuit equippedwith a control or regulating valve according to the invention;

[0065]FIG. 36 is a perspective view of a control valve, of the three-waytype, according to another embodiment of the invention;

[0066]FIG. 37 is a side view of the valve of FIG. 36;

[0067]FIGS. 38, 39 and 40 are views in radial section of the valve ofFIGS. 36 and 37, passing respectively through the axes of the threeoutlet nozzles;

[0068]FIGS. 41, 42 and 43 are views in section on XLI-XLI, XLII-XLII andXLIII-XLIII of FIG. 37;

[0069]FIG. 44 is a side view of the adjusting member of the valve ofFIGS. 36 to 43;

[0070]FIG. 45 is a perspective view of the adjusting member of FIG. 44;

[0071]FIGS. 46 and 47 are views similar to FIGS. 44 and 45 respectively,the adjusting member being equipped with a split ring;

[0072]FIG. 48 shows, in each instance, three different sectional viewsof the valve of FIGS. 36 to 43 for angular positions of the adjustingmember, numbered from 1 to 36, which follow on from one another inten-degree increments in the clockwise direction;

[0073]FIGS. 49 and 50 depict a control valve with built-in sensors; and

[0074]FIG. 51 depicts a drive wheel comprising circular electricalcontact tracks.

[0075] Reference is made first of all to FIGS. 1 to 8 which show acontrol valve 10 according to a first embodiment of the invention. Thiscontrol valve comprises a cylindrical body 12 limited by an end wall 14and a cylindrical side wall 16 of axis XX. A fluid inlet nozzle 18 opensaxially into the end wall 14. Three fluid outlet nozzles 20, 22 and 24open into the cylindrical side wall 16. These three outlet nozzles openat axial heights and at angular positions that are chosen with respectto the axis of rotation XX. In the example, the nozzles 20, 22 and 24open radially into the wall 16. The nozzles 20 and 24 are diametricallyopposed, while the nozzle 22 makes an angle of 90 degrees with respectto the common axis of the nozzles 20 and 24. Furthermore, the nozzles20, 22 and 24 have successively decreasing diameters.

[0076] Housed inside the valve body 12 is an adjusting member 26, alsoknown as the rotary member, which is produced in the form of a solidcylindrical element which may be made of plastic. The diameter of thecylindrical element more or less corresponds to the inside diameter ofthe valve body. The adjusting member 26 is continued by a stem 28directed along the axis XX. This stem 28 passes through a centralopening possessed by a cover 30 of circular shape screwed onto a flange32 of the valve body by four fixing screws 34 with the interposition ofa seal (not depicted). The adjusting member 26 is able to be driven inrotation about the axis XX by drive means 36 depicted schematically inFIG. 1. The drive means may for example consist of a motor of thestepping type able to bring the adjusting member 26 into a multitude ofdifferent positions, either in successive increments or continuously.

[0077] According to one essential feature of the invention, theadjusting member 26 comprises a truncated end 38 which faces toward theend wall 14 (as can be seen best in FIG. 5). In the example, thistruncated end is formed of a generally flat face 40 which, with the axisof rotation XX, makes a chosen angle which, in the example, is close to45 degrees.

[0078] In that way, the adjusting member 26 allows control over thefluid outlets 20, 22 and 24, with a law defined as a function of theangular position of said member in the valve body.

[0079] In the position depicted in FIGS. 5 to 8, the fluid which arrivesthrough the inlet nozzle 18 can escape only through the outlet nozzle24, the other outlet nozzles 20 and 22 being closed.

[0080] By subsequently altering the angular position of the adjustingmember it is possible to adjust the flow rate of fluid through thevarious outlet nozzles 20, 22 and 24, and to do so progressively.

[0081] The position of the adjusting member 26 is controlled by means ofa position sensor 331 placed, for example, on the drive wheel 33 of thereduction gearbox 3 of the drive means 36 (FIG. 51). This sensor 331 maybe a potentiometer with a circular contact track fixed directly to thedrive wheel 33.

[0082] The adjusting member 26 depicted in FIGS. 9 to 11 is similar tothat of the preceding embodiment except that the truncated end 38 has aduct 42 of chosen shape which, here, is more or less in the shape of anarc of a circle centered around the axis XX. This duct in the shape ofan arc of a circle extends over roughly 90 degrees, as can be seen inFIGS. 12 to 15, which correspond to FIGS. 5 to 8 respectively of thepreceding embodiment.

[0083] The presence of this duct makes it possible to achieveprogressiveness in the opening of the valve over two ways of this valve,namely the outlet nozzles 22 and 24.

[0084] The position of the adjusting member 26 of FIGS. 12 to 15corresponds to that of the adjusting member 26 of FIGS. 5 to 8. However,the presence of this duct means that a small fluid flow rate can escapethrough the outlet nozzle 22 even though this outlet nozzle iscompletely closed in the case of the preceding embodiment. By contrast,here again, the outlet nozzle 20 is closed by the adjusting member 26.

[0085] Reference is now made to FIGS. 16 to 18 which show an adjustingmember 26 similar to that of the embodiment of FIGS. 1 to 8. The maindifference lies in the fact that this member here is equipped with asealing shoe 44 of cylindrical shape, housed in a housing 46 formed atthe periphery of the rotary member and urged by a spring 48. This shoeprovides sealing at the most critical part of the circuit. The presenceof the spring provides compensation for the variations in expansion ofthe materials, because of the variations in temperature of the fluidpassing through the valve.

[0086] In FIGS. 19 to 22 which can be likened respectively to FIGS. 5 to8, the sealing shoe 44, in the positioned depicted, seals against thenozzle 20.

[0087] Reference is now made to FIGS. 23 to 30 which can be likened toFIGS. 1 to 8 respectively, the adjusting member 26 here being equippedwith a shoe 44 as in the preceding embodiment. The main difference herelies in the fact that the nozzles 20 and 24 open tangentially into thevalve body 12 whereas the nozzle 22 opens radially thereinto.

[0088] Reference is now made to FIGS. 31 to 33 which show an adjustingmember similar to that of FIGS. 1 to 8. The adjusting member is coveredby a split ring 50 which comprises a slot 52 for the passage of a lug 54formed radially projecting from the adjusting member. The result is thatthis split ring is made to rotate as one with the adjusting member 26.The split ring 50 is made of a material with a low coefficient offriction, for example Teflon® (polytetrafluoroethylene), PPA or PPS,with or without a surface coating.

[0089] Furthermore, this split ring has an outside diameter slightlygreater than the inside diameter of the valve body prior to mounting andan inside diameter slightly greater than the diameter of the adjustingmember after mounting. That makes it possible to guarantee sealedcontact of the ring with the body, and for this to be the case withoutleading to an excessively high torque.

[0090] Reference is now made to FIG. 34 which shows various successivepositions of the adjusting member, these being numbered from 1 to 21,each one respectively depicted at the three outlet nozzles 20, 22 and24. In the example, these positions are obtained by successive rotationsthrough 15 degrees, in the clockwise direction, of the adjusting memberinside the valve body. It may thus be seen that the various outletnozzles can be opened or closed in accordance with a defined law, andthat this can be done progressively.

[0091] These various positions are obtained by the drive means 36 whichare operated by an appropriate control circuit.

[0092] Reference is now made to FIG. 35 which shows a circuit 60 forcooling the engine 62 of a motor vehicle. The circuit 60 has, passingthrough it, a coolant, typically water to which an antifreeze is added,which flows under the action of a pump 78. The fluid is heated by theengine, leaves the latter via an outlet 64 connected to the inlet nozzle18 of a control valve 10 of the type described hereinabove. This valvecomprises three outlet nozzles 20, 22 and 24 which are connected tothree branches of the circuit. This circuit comprises a first branch 66which contains a cooling radiator 68 and an expansion vessel 70, abranch 72 which forms a bypass bypassing the cooling radiator 68 and abranch 74 which contains a unit heater 76 used to heat the cabin of thevehicle. The nozzle 20 is connected to the branch 66 (radiator), thenozzle 22 to the branch 74 (unit heater) and the nozzle 24 to the branch72 (bypass).

[0093] The valve thus makes it possible to have independent control overthe flow rates of fluid in the aforementioned branches, so as tooptimize the engine temperature and the heating of the cabin.

[0094] In particular, when the engine is being started from cold, itallows the fluid to be circulated through the bypass branch 72 withoutpassing the radiator 68. During this start phase it is also possible tocause some or all of the fluid flow rate to pass into the unit heater76, if heating is desired.

[0095] When the temperature of the fluid has reached or exceeded a giventhreshold value, the fluid passes through the radiator 68 and avoids thebypass 72. Furthermore, depending on whether or not heating is desired,some of the fluid may or may not pass through the unit heater 76.

[0096] The control valve in FIGS. 36 to 47 can be likened to thosedescribed before, the common elements being denoted by the samenumerical references.

[0097] The outlet nozzles 20 and 22 together form an angle of close to90°, while the outlet nozzle 24 extends between the nozzles 20 and 22.In addition, the outlet nozzle 24, which is the one closest to the cover30, has a diameter greater than the diameter in the precedingembodiments. As a result, it would normally be necessary to increase thediameter of the valve body. To avoid that, the adjusting member 26comprises, at the opposite end to the truncated end 38, two roughlydiametrically opposed cylindrical wall portions 78 and 80 forcontrolling the outlet nozzle 24.

[0098] These two wall portions 78 and 80 extend the adjusting member 26in the direction away from the truncated end 38 and are produced in theform of two thin webs of material extending some distance from the stem28 of the adjusting member. It can be seen, particularly from FIGS. 39to 41, how these two wall portions allow access to the outlet nozzle 24to be closed or opened according to the angular position of theadjusting member.

[0099] In this embodiment, the adjusting member 26 comprises aperipheral region 82 which is equipped with circular grooves 84 (seeFIGS. 44 and 45 in particular). As in the preceding embodiments, theadjusting member 26 takes a split ring 50. The latter covers both theperipheral region 82 and the two wall portions 78 and 80. The functionof these circular grooves 84 is to press the split ring 50 firmlyagainst the interior wall of the valve body under a pressure difference,making it possible to ensure good sealing during operation.

[0100] The valve of FIGS. 36 to 47 finds a particular use in a circuitof the type depicted in FIG. 35. In this case, the nozzle 20 isconnected to the branch 66 (radiator), the nozzle 22 to the branch 74(unit heater) and the nozzle 24 to the branch 72 (bypass).

[0101] Reference is now made to FIG. 48 which shows various successivepositions of the adjusting member, numbered from 1 to 36, each onerespectively at the three outlet nozzles 20, 22 and 24. In the example,these positions are obtained by successive rotations through 10 degreesin the clockwise direction of the adjusting member within the valvebody. It can thus be seen that the various outlet nozzles can be openedor closed in accordance with a defined law, and that this can be doneprogressively.

[0102] With reference to FIG. 49 and 50 it is possible to incorporatesensors into the control valve according to the invention. The controlvalve does actually allow sensors to be incorporated into the adjustingmember 26 rotating about the axis XX. All kinds of sensors capable ofmeasuring parameters relating to the engine cooling circuit and, forexample:

[0103] a coolant temperature sensor,

[0104] a sensor sensing the temperature of an at-risk component on thevalve actuator,

[0105] a pressure sensor sensing the pressure in the cooling circuit toanticipate any overheating of the engine and to trigger a degraded modefor the valve, the fan and the pump and then of the engine if necessary,

[0106] a sensor that senses the presence of air in the coolant, etc.,may be sited in the adjusting member 26.

[0107]FIG. 49 illustrates the incorporation of sensors into an adjustingmember with a truncated end 38. A temperature sensor sensing thetemperature of coolant 5 and a sensor sensing the presence of air in thecoolant 13 are incorporated into the adjusting member 26. These sensorsare made up of two electrodes. A cylindrical duct 7 is machined in theadjusting member 26 to house the sensors 13 and 5.

[0108] The cylindrical duct 7 comprises a brass end 51 in contact withthe coolant, regardless of the position of the adjusting member. Thetemperature sensor 5 is introduced into the cylindrical duct in such away that its lower end is housed in the brass end. Thus, the temperaturesensor may measure the temperature of the coolant even when theadjusting member is rotating about the axis XX.

[0109] There are various alternative forms of embodiment forincorporating the sensors. The adjusting member 26 is shaped to be ableto house the sensors, taking account in particular of the nature of thesensor and of its shape. Incorporation of the sensors 5 and 13 is givenby way of nonlimiting example. Other forms of incorporation arepossible.

[0110] For example, the sensor sensing the presence of air in thecoolant 13 comprises a first part introduced into the cylindrical ductwhile its lower end passes through the adjusting member 26 as far as itstruncated end 28, on the outside of the cylindrical duct, to be incontact with the coolant.

[0111] In all the alternative forms of embodiment, the lower ends of thesensors pass through the lower end of the adjusting member 26 whichfaces toward the end wall 14. In this way, the sensor 13 can also be incontact with the coolant independently of the angular position of theadjusting member. It can then measure values relating to the presence ofair in the coolant.

[0112] The values measured by the sensors are then transmitted to theoutside of the valve for processing intended to monitor the coolingcircuit and to diagnose any malfunctions that may occur.

[0113] Reference is now made to FIG. 50 which is a view from above ofthe valve depicted in FIG. 49. In this figure, the drive wheel 33 of thereduction gearbox 3 comprises circular tracks 17. The circular tracksare therefore also able to move. As an alternative, the circular trackscan be arranged on another moving part of the valve separate from thedrive wheel, for example on a printed circuit mounted in parallel withthe drive wheel.

[0114] Advantageously, the upper ends of the sensors are connected tothese circular tracks by electrical contact to allow the relativemovement of the adjusting member with respect to the valve body 12 andprevent the wires from twisting. This connection allows the sensors totransmit the measured values to the circular tracks.

[0115] The circular tracks are connected to plugs of the brush type 19,placed on a fixed part of the valve, for example on the printed circuitthat accommodates the microprocessor 39 that operates the valve or onthe protective casing 8 protecting the external components of the valvesuch as the reduction gearbox 3 or the drive wheel 33. These plugstransmit the information received from the circular tracks to a singleconnector 37. Given the grouping of the upper ends of the sensors, thereis no longer actually any need to use numerous connectors for conveyingthe measured values to the microprocessor and/or to the computer.

[0116] The connector 37 then transmits the information relating to thevalues measured by the sensors to the microprocessor which operates thevalve (power supply, control and diagnostics signal) and/or to thevehicle computer, supplying it with the data needed for engine mapping,such as the coolant temperature.

[0117] As an alternative, a decision may be made to locate the circulartracks 17 on one of the fixed parts of the valve and the plugs 19 on oneof the moving parts of the valve.

[0118] Furthermore, the circular tracks may be replaced by otherinformation transmitting means capable of transmitting data from theupper ends of the sensors to the connector, such as contactless sensorsfor example, particularly Hall-effect, optical or magneto-resistivesensors.

[0119] Incorporating the sensors inside the valve, according to theinvention, allows the operation of the cooling circuit to be monitoredand breakdowns to be diagnosed as and when they occur. In a degradedmode, it also allows the operation of the valve to be adjusted. Thevalve can thus by itself regulate the engine temperature and diagnoseany breakdowns of actuators (fan, pump, valve, leak of fluid, etc.) atthe computer before the engine overheats.

[0120] Incorporating the sensors into the control valve according to theinvention guarantees better prevention and gives the engine betterdependability. Furthermore, it makes it possible to reduce the number ofparts and the cost of the function of regulating the cooling circuit.

[0121] Of course, the valve of the invention can be embodied in manyalternative forms. It is not restricted to a three-way valve as in theembodiments described above. Nor is it limited to an application to amotor vehicle engine cooling circuit.

[0122] Likewise, it is possible to conceive of an embodiment in whichthe inlets and the outlets are reversed on the valve body. Indeed,within the meaning of the invention, the ideas of “fluid inlet” and“fluid outlet” are defined with respect to the position of the valve inthe cooling circuit. In other embodiments, for example when the valve isplaced on the inlet side of the engine (62) in the cooling circuit, theideas of “fluid inlet” and “fluid outlet” are reversed and, in thiscase, the nozzle 18 is a fluid outlet and the nozzles 20, 22 and 24 arefluid inlet nozzles.

1. A control valve for a fluid circulation circuit, comprising a bodywhich is equipped with at least one fluid inlet and at least two fluidoutlets, and which delimits a housing for an adjusting member able torotate about an axis of rotation and to adopt various angular positionsin order to control the distribution of fluid through the outlets,wherein the body comprises an end wall into which the fluid inlet opensand a side wall into which the fluid outlets open, at axial heights andat angular positions that are chosen with respect to the axis ofrotation, and wherein the adjusting member comprises a shaped part forcontrolling the outlets of fluids with a law defined as a function ofthe angular position of the rotary member in the valve body.
 2. Thecontrol valve as claimed in claim 1, wherein the body delimits acylindrical housing for the adjusting member, wherein the side wall is acylindrical wall, and wherein the shaped part is a truncated end facingtoward the end wall.
 3. The control valve as claimed in claim 2, whereinthe truncated end comprises a generally flat face which, with the axisof rotation, forms a chosen angle of close to 45°.
 4. The control valveas claimed in one of claims 2 and 3, wherein at least one of the fluidoutlets is a radial nozzle.
 5. The control valve as claimed in one ofclaims 2 and 3, wherein at least one of the fluid outlets is atangential nozzle.
 6. The control valve as claimed in one of claims 1 to5 and which comprises three fluid outlets.
 7. The control valve asclaimed in one of claims 1 to 6, wherein the adjusting member is coveredwith a split ring made to rotate as one with it by a projecting lug thatthe adjusting member has.
 8. The control valve as claimed in claim 7,wherein the split ring is made of a material with a low coefficient offriction.
 9. The control valve as claimed in one of claims 7 and 8,wherein the split ring has an outside diameter slightly greater than theinside diameter of the valve body prior to mounting and an insidediameter slightly greater than the diameter of the adjusting memberafter mounting.
 10. The control valve as claimed in one of claims 7 to9, wherein the split ring covers a region of the adjusting member whichis equipped with circular grooves.
 11. The control valve as claimed inone of claims 1 to 10, wherein the truncated end of the adjusting membercomprises a duct, having a chosen shape, advantageously the shape of anarc of a circle.
 12. The control valve as claimed in one of claims 1 to11, wherein the adjusting member is equipped with a sealing shoe. 13.The control valve as claimed in claim 12, wherein the sealing shoe ismounted on a spring.
 14. The control valve as claimed in one of claims 1to 13, wherein the adjusting member comprises, at the opposite end tothe truncated end, two roughly diametrically opposed cylindrical wallportions for controlling one of the fluid outlets.
 15. The control valveas claimed in one of claims 1 to 14 and which comprises drive means ableto drive the adjusting member by means of a drive wheel forming part ofa reduction gearbox for bringing it into chosen angular positions withrespect to the valve body.
 16. The control valve as claimed in claim 15,wherein the valve comprises a microprocessor for operating the drivemeans.
 17. The control valve as claimed in one of the preceding claims,wherein the adjusting member comprises at least one internal sensor formeasuring values relating to the operation of the fluid circulationcircuit.
 18. The control valve as claimed in claim 17, wherein theinternal sensors are sensors that sense the presence of air in thecircuit.
 19. The control valve as claimed in claim 17, wherein theadjusting member comprises a machined duct extending over the entirelength of the adjusting member, to house the sensors.
 20. The controlvalve as claimed in claim 17, wherein a first end of the sensors passesthrough the lower end of the adjusting member facing toward the endwall, at a chosen point, so as to be in contact with the fluid and takemeasurements.
 21. The control valve as claimed in claim 20, wherein thesensors are temperature sensors and wherein the machined duct comprisesa lower end made of brass, in contact with the fluid, in which to housethe first end of the sensors.
 22. The control valve as claimed in claim20, wherein the second end of the sensors passes through the upper endof the valve toward the outside to transmit the values measured by thesensors.
 23. The control valve as claimed in claim 22, wherein thesecond end of the sensors is connected to information transmitting meansfor transmitting the values measured by the sensors to themicroprocessor and/or to a computer.
 24. The control valve as claimed inclaim 23, wherein the information transmitting means comprise circularelectrical-contact tracks.
 25. The control valve as claimed in claim 24,wherein the information transmitting means comprise plugs connected tothe circular tracks for transmitting the values originating from thesensors.
 26. The control valve as claimed in claim 25, wherein thecircular tracks are situated on a moving part of the valve and whereinthe plugs are situated on a fixed part of the valve.
 27. The controlvalve as claimed in claim 25, wherein the circular tracks are situatedon a fixed part of the valve and wherein the plugs are situated on amoving part of the valve.
 28. The control valve as claimed in one ofclaims 26 and 27 taken in combination with claim 15, wherein the movingpart of the valve is the drive wheel of the drive means.
 29. The controlvalve as claimed in claim 23 taken in combination with claim 16, andwhich comprises a connector, connected to the information transmittingmeans of the valve to transmit the measured values to the microprocessorand/or to the computer.
 30. A fluid circulation circuit which comprisesa control valve as claimed in one of claims 1 to 31, the fluid inlet ofwhich is connected to a fluid source and the fluid outlets of which areconnected respectively to branches of the circuit.
 31. The fluidcirculation circuit as claimed in claim 30 and which is produced in theform of a cooling circuit for cooling the engine of a motor vehicle,through which a coolant flows under the action of a circulation pump,this circuit being one wherein the control valve is a three-way valve,the fluid inlet of which is connected to a coolant inlet originatingfrom the engine, and the three fluid outlets of which are connectedrespectively to a first branch of the circuit which contains a coolingradiator, a second branch of the circuit which constitutes a bypass ofthe cooling radiator, and to a third branch of the circuit whichcontains a unit heater for heating the cabin.